1. Field of the Invention
The present invention relates to a recording medium.
2. Description of the Related Art
Silica can form a porous structure showing high ink-absorbing properties and is therefore suitable as inorganic particles that are used in the ink-receiving layer of a recording medium. In general, silica is roughly classified based on the production process into wet method and dry method (gas-phase method). In particular, the silica prepared by the dry method (gas-phase method) (hereinafter, also referred to as “gas-phase method silica”) has a particularly large specific surface area and thereby shows particularly high ink-absorbing properties. In addition, the silica has a low refractive index and thereby makes the transparency of the ink-receiving layer high to give good color development of an image.
Japanese Patent Laid-Open No. 2001-341418 discloses a method of enhancing the ozone resistance of an image by a recording medium having an ink-receiving layer containing such gas-phase method silica. This Patent Literature describes an improvement in the ozone resistance of an image by an ink-receiving layer containing an amino compound having repeating alkylene oxide groups and a diallylamine hydrochloride-sulfur dioxide copolymer as a cationic polymer, in addition to gas-phase method silica and polyvinyl alcohol as a binder.
Japanese Patent Laid-Open Nos. 2005-280035 and 2004-262232 describe improvements in the bleed resistance and color development of an image by a recording medium having an ink-receiving layer prepared by laminating a finish coat layer containing a cationic polymer on an undercoat layer containing a pigment and a binder.
However, according to the investigation by the present inventors, though the ozone resistance of an image is improved in the recording medium described in Japanese Patent Laid-Open No. 2001-341418, cracking occurs in the ink-receiving layer. In Japanese Patent Laid-Open No. 2005-280035, since gas-phase method silica is not used, the intended color development of an image is not obtained. In Japanese Patent Laid-Open No. 2004-262232, though gas-phase method silica is used, a bronze phenomenon occurs in the resulting image.